A5037882079- Cosmology and Gravitation Theories
- Galaxies: Formation, Evolution, Phenomena
- Dark Matter and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Astronomy and Astrophysical Research
- Particle physics theoretical and experimental studies
- Astrophysics and Cosmic Phenomena
University of Iceland
2019-2021
RWTH Aachen University
2017
Several interesting Dark Matter (DM) models invoke a dark sector leading to two types of relic particles, possibly interacting with each other: non-relativistic DM, and relativistic Radiation (DR). These have consequences for cosmological observables, could in principle solve problems like the small-scale cold DM crisis, Hubble tension, and/or low $\sigma_8$ value. Their behaviour is captured by ETHOS parametrisation, which includes DR-DM scattering rate scaling power-law temperature, $T^n$....
One of the open questions in modern cosmology is small scale crisis cold dark matter paradigm. Increasing attention has recently been devoted to self-interacting models as a possible answer. However, solving so-called "missing satellites" problem requires addition presence an extra relativistic particle (dubbed radiation) scattering with early universe. Here we investigate impact different theoretical devising radiation interactions on large cosmological observables. We use cosmic microwave...
ABSTRACT We perform a series of cosmological hydrodynamic simulations to investigate the effects non-gravitational dark matter (DM) interactions on intergalactic medium (IGM). In particular, we use Ethos framework compare statistics Lyman-α forest in cold (CDM) with an alternative model which DM couples strongly relativistic species early universe. These models are characterized by cut-off linear power spectrum, followed ‘dark acoustic oscillations’ (DAOs) sub-dwarf scales. While primordial...
Upcoming data of the 21-cm hydrogen line during cosmic dawn ($z\sim 10-30$) will revolutionize our understanding astrophysics first galaxies. Here we present a case study on how to exploit those same measurements learn about nature dark matter (DM) at small scales. Focusing Effective Theory Structure Formation (ETHOS) paradigm, run suite simulations covering broad range DM microphysics, connecting output $N$-body dedicated predict evolution signal across entire dawn. We find that...
We propose two effective parameters that fully characterise galactic-scale structure formation at high redshifts ($z\gtrsim5$) for a variety of dark matter (DM) models have primordial cutoff in the power spectrum. Our description is within recently proposed ETHOS framework and includes standard thermal Warm DM (WDM) with acoustic oscillations (DAOs). To define explore this parameter space, we use high-redshift zoom-in simulations cover wide range non-linear scales from those where should...
We study the halo mass function and inner structure at high redshifts ($z\geq5$) for a suite of simulations within formation ETHOS framework. Scenarios such as cold dark matter (CDM), thermal warm (WDM), acoustic oscillations (DAO) various strengths are contained in with just two parameters $h_{\rm peak}$ $k_{\rm peak}$, amplitude scale first DAO peak. The Extended Press-Schechter (EPS) formalism smooth-$k$ filter is able to predict cut-off created by suppression small power models...